925 results about "Relative phase" patented technology

Exemplary apparatus and process can be provided for imaging information associated with at least one portion of a sample. For example, (i) at least two first different wavelengths of at least one first electro-magnetic radiation can be provided within a first wavelength range provided on the portion of the sample so as to determine at least one first transverse location of the portion, and (ii) at least two second different wavelengths of at least one second electro-magnetic radiation are provided within a second wavelength range provided on the portion so as to determine at least one second transverse location of the portion. The first and second ranges can east partially overlap on the portion. Further, a relative phase between at least one third electro-magnetic radiation electro-magnetic radiation being returned from the sample and at least one fourth electro-magnetic radiation returned from a reference can be obtained to determine a relative depth location of the portion. First information of the portion based on the first transverse location and the relative depth location, and second information of the portion based on the second transverse location and the relative depth location can be obtained. The imaging information may include the first and second information.

A method and system for locating an RF transponder based on phase differences between signals received from the RF transponder. The method includes receiving a signal from the transponder and calculating distance, relative movement, and position by comparing I-Q phase angle vectors of the signals. Global scroll commands can be used following receipt of signals at first and second frequencies to quickly determine distance.

A method, apparatus, and system are provided which enables the control of contactless power transfer in an inductive power transfer system using a phase control technique. The method comprises adjusting the phase of a secondary-side converter output voltage with respect to that of a primary-side converter. The magnitude of power transfer is determined by the relative phase angle, and the direction of power transfer is determined by whether the secondary converter output voltage leads or lags the input converter voltage, thereby enabling bi-directional power transfer between the primary and secondary sides of the system. According to alternative embodiments, the method may also be used for uni-directional power transfer only, and/or the secondary converter may be operated to maintain a constant relative phase angle.

A system and method for determining the relative phase of each of a plurality of load meters connected to a three-phase power distribution system. The system includes a gateway that communicates information to and from each of the individual load meters. The gateway generates a timing pulse that is received by each of the load meters. Based upon the delay from the receipt of the timing pulse to the next zero crossing of the single phase power supply received by the meter, the utility can determine the phase of the individual meter. The system can include a feeder meter connected to each phase of the electrical supply system to determine the energy consumption for each of the meters connected to a specific phase. The utility can compare the energy consumption information from the feeder meter to all of the load meters connected to the same phase to determine whether any energy theft is occurring.

In a cellular mobile telecommunications system the position of a mobile station can be estimated in terms of its bearing and range from a cell site. A multi-element direction finding antenna at the cell site receives signals from the mobile station and a receiver circuit estimates the bearing using the relative phase of signals received at different antenna elements and estimates the range by measuring round trip delay of signals to and from the mobile station. Motion of the mobile station can introduce errors into the bearing estimate due to frequency offset and frequency spread when element sampling is non-simultaneous. Compensation for these errors is introduced by using signal samples successively received at the same antenna element to estimate Doppler frequency offset and spread. It is necessary to ensure accurate calibration of the direction finding antenna and the receiver circuit. This is done by injecting calibration signals into the circuit near the antenna or into the antenna itself from a near field probe. Other aspects of calibration, such as antenna position, are calibrated using a remote beacon. A beacon emulating a mobile station but at a fixed, known location, or a beacon at an adjacent cell site may be used.

A system, apparatus, and method for determining the distance between two objects using an indirect propagation delay measurement is disclosed. A frequency hopping scheme (such as the Bluetooth™ technology) is used to measure the relative phase offset of the received signal between the various frequencies. For a given distance between the objects, the phase offset vs. frequency curve is a straight line with the slope dependent upon the measured distance. After the phase of the received signals is detected, the data is plotted on a curve and the slope is calculated.

A phase-difference sensor measures the spatially resolved difference in phase between orthogonally polarized reference and test wavefronts. The sensor is constructed as a pixelated phase-mask aligned to and imaged on a pixelated detector array. Each adjacent pixel of the phase-mask measures a predetermined relative phase shift between the orthogonally polarized reference and test beams. Thus, multiple phase-shifted interferograms can be synthesized at the same time by combining pixels with identical phase-shifts. The multiple phase-shifted interferograms can be combined to calculate standard parameters such as modulation index or average phase step. Any configuration of interferometer that produces orthogonally polarized reference and object beams may be combined with the phase-difference sensor of the invention to provide, single-shot, simultaneous phase-shifting measurements.

A scanning control circuit generates a clock signal corresponding to an expected scan timing of a resonant scanner. In one approach, the control circuit uses a pair of direct digital synthesis (DDS) integrated circuits. A first DDS chip provides a system clock that is synchronized to the monitored period of the scanner. A second DDS chip generates a frequency chirped signal that has a frequency profile corresponding to a desired pixel clock timing. To control phase precisely, four complementary clock signals are weighted and mixed at light source drivers to produce relative phase shifts for different light sources.

A polarization grating includes a substrate and a first polarization grating layer on the substrate. The first polarization grating layer includes a molecular structure that is twisted according to a first twist sense over a first thickness defined between opposing faces of the first polarization grating layer. Some embodiments may include a second polarization grating layer on the first polarization grating layer. The second polarization grating layer includes a molecular structure that is twisted according to a second twist sense that is opposite the first twist sense over a second thickness defined between opposing faces of the second polarization grating layer. Also, a switchable polarization grating includes a liquid crystal layer between first and second substrates. The liquid crystal layer includes liquid crystal molecules having respective relative orientations that are rotated over a thickness defined between opposing faces thereof by a twist angle that is different from a relative phase angle between respective first and second periodic alignment conditions of the first and second substrates. Related devices and fabrication methods are also discussed.

An optical mixer that, in one embodiment, has a single optical hybrid optically coupled to a single polarization beam splitter. The optical hybrid mixes a polarization-multiplexed optical communication signal and a local-oscillator signal to generate four mixed signals, each corresponding to a different relative phase shift between the communication and local-oscillator signals. The polarization beam splitter separates each of the mixed signals into two polarization components, subsequent processing of which enables an optical receiver employing the optical mixer to recover the data carried by the communication signal.

A method for improving vibratory source seismic data uses a filter which converts a recorded seismic groundforce signal (including harmonic distortion therein) into a desired short-duration wavelet. A plurality of surveys may be carried out using a plurality of sweeps from plurality of vibrators that have their relative phases encoded, the groundforce signal of each vibrator being measured. The recorded seismic reflection signals are then processed to separate out the signals from each vibrator. In another aspect, harmonics of upto any desired order may be canceled while carrying out multiple surveys with a plurality of vibrators. In a marine environment, the recorded signal from a vibrator towed by a moving vessel is used to derive a Doppler shift correction filter that is applied to reflection seismic data.

A receiver (50) includes a self-calibrating receive path correction system for correction of I/Q gain and phase imbalances in a radio frequency signal. The system includes a signal-processing block (53), an I/Q phase imbalance detection and correction circuit (98), an I/Q gain imbalance detection and correction circuit (96), and an adaptive loop bandwidth control circuit (102). The I/Q phase imbalance detection and correction circuit (98) equalizes for the relative phase imbalance and the I/Q gain imbalance detection and correction circuit (96) equalizes for the relative gain imbalance between the I and Q channels created by the analog portion of a quadrature receiver. The adaptive loop bandwidth control circuit (102) dynamically adjusts at least one loop bandwidth for the I/Q gain imbalance detection and correction circuit (96) and the I/Q phase imbalance detection and correction circuit (98) on a slot boundary.

Metrology targets are formed by a lithographic process, each target comprising a bottom grating and a top grating. Overlay performance of the lithographic process can be measured by illuminating each target with radiation and observing asymmetry in diffracted radiation. Parameters of metrology recipe and target design are selected so as to maximize accuracy of measurement of overlay, rather than reproducibility. The method includes calculating at least one of a relative amplitude and a relative phase between (i) a first radiation component representing radiation diffracted by the top grating and (ii) a second radiation component representing radiation diffracted by the bottom grating after traveling through the top grating and intervening layers. The top grating design may be modified to bring the relative amplitude close to unity. The wavelength of illuminating radiation in the metrology recipe can be adjusted to bring the relative phase close to π/2 or 3π/2.

Detector signals in a pulse oximeter are analyzed to determine a quality of the signals in relation to desired information content or artifact content. The analysis involves performing a transform on a signal to obtain frequency related information and analyzing the frequency related information to obtain a value independent of a shape and waveform of a spectrum of the time-based signal. In one implementation, the analysis involves the relative amplitude or power measures of corresponding peaks in the red and infrared spectra. For example, the ratio of the amplitude of the fundamental peak in the red spectrum and the amplitude of the fundamental peak in the infrared spectrum may be tracked over time. In another implementation, the analysis involves consideration of the relative phase of the fundamental and harmonic components of a signal. In either case, signals including desired physiological information can be distinguished from artifact affected signals. Based on this analysis, signals can be validated or an appropriate processing algorithm can be selected.